SpringMVC使用MultipartFile 实现异步上传方法介绍

<dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.1</version>
    </dependency>
    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.2</version>
    </dependency>
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.1.37</version>
    </dependency>

<bean id="multipartResolver"
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="defaultEncoding" value="UTF-8"></property>
    <property name="maxUploadSize" value="5400000"></property>
  </bean>

<form id="uploadForm" name="uploadForm"
    enctype="multipart/form-data">
<input name="messageContent" value="多个参数的情况下">
      <label>文件</label> <input type="file" name="file">
      <button class="btn" type="button" id="doSave">提交</button>
  </form>
</body>
</html>

<script type="text/javascript" src="js/jquery-1.6.2.min.js"></script> 
<script type="text/javascript" src="js/jquery-ui.min.js"></script> 
<script type="text/javascript" src="js/jquery.form.js"></script> 

<script>
  $(function() {
    $("#doSave")
        .click(
            function() {
              $("#uploadForm")
                  .ajaxSubmit(
                      {
                type : 'post',
                url : "/tmpInfo/method2.do",
    //data: //注意只要是写在表单里面的，都不需要加这个属性。在controller中可以根据@RequestParam String str获取到属性值。  
  contentType : "application/x-www-form-urlencoded; charset=utf-8",
    success: function(data) {
         //接受到的data还只是一个字符串，需要转成json对象
         var obj = JSON.parse(data);
         if(obj.flag==true){
          alert("上传成功");
       }else{
         alert("error");
       }
        },
        error: function (data)//服务器响应失败处理函数
        {
          alert("出错");
        } 
       });
  });
  }); 

 @RequestMapping("/method2") 
    @ResponseBody
    public String method2(@RequestParam MultipartFile file,
        @RequestParam String messageContent ) { 
        //多个参数的话只要多个@RequestParam即可，注意参数名要和表单里面的属性名一致
     JSONObject json =new JSONObject();
     System.out.println(messageContent);
      String orgiginalFileName = ""; 
      int m =new Random().nextInt(100)+10;
      System.out.println("m="+m);
      String path="D:/"+m+"b.txt";
      try { 
        File newFile =new File(path);
        file.transferTo(newFile);
        String fileName = file.getName(); 
        InputStream inputStream = file.getInputStream(); 
        String content = file.getContentType(); 
        orgiginalFileName = file.getOriginalFilename(); 
        System.out.println("fileName: "+fileName+", inputStream: "+ inputStream 
              +"\r\n content: "+content+", orgiginalFileName: ="+ orgiginalFileName 
              +"\r\n projectName: ");   
      } catch (IOException e) { 
        e.printStackTrace(); 
      } 
      json.put("flag", true);
      json.put("message", "success");
      System.out.println(json.toJSONString());
      return json.toJSONString(); 
    }